An establishment is a single physical location at which business is conducted. It is not necessarily identical with a company or enterprise, which may consist of one establishment or more. Wholesale trade figures represent a summary of reports for individual establishments rather than companies. For cases where a census report was received, separate information was obtained for each location where business was conducted. When administrative records of other federal agencies were used instead of a census report, no information was available on the number of locations operated. Each wholesale trade establishment was tabulated according to the physical location at which the business was conducted. The count of establishments represents those in business at any time during 2002.

When two activities or more were carried on at a single location under a single ownership, all activities generally were grouped together as a single establishment. The entire establishment was classified on the basis of its major activity and all data for it were included in that classification. However, when distinct and separate economic activities (for which different industry classification codes were appropriate) were conducted at a single location under a single ownership, separate establishment reports for each of the different activities were obtained in the census.